@@ -17249,6 +17249,7 @@ F: include/uapi/linux/virtio_*.h
F: drivers/crypto/virtio/
F: mm/balloon_compaction.c
F: include/linux/mdev_virtio_ops.h
+F: samples/vfio-mdev/mvnet.c
VIRTIO BLOCK AND SCSI DRIVERS
M: "Michael S. Tsirkin" <mst@redhat.com>
@@ -131,6 +131,16 @@ config SAMPLE_VFIO_MDEV_MDPY
mediated device. It is a simple framebuffer and supports
the region display interface (VFIO_GFX_PLANE_TYPE_REGION).
+config SAMPLE_VIRTIO_MDEV_NET
+ tristate "Build VIRTIO net example mediated device sample code -- loadable modules only"
+ depends on VIRTIO_MDEV && VHOST_RING && m
+ help
+ Build a networking sample device for use as a virtio
+ mediated device. The device coopreates with virtio-mdev bus
+ driver to present an virtio ethernet driver for
+ kernel. It simply loopbacks all packets from its TX
+ virtqueue to its RX virtqueue.
+
config SAMPLE_VFIO_MDEV_MDPY_FB
tristate "Build VFIO mdpy example guest fbdev driver -- loadable module only"
depends on FB && m
@@ -3,3 +3,4 @@ obj-$(CONFIG_SAMPLE_VFIO_MDEV_MTTY) += mtty.o
obj-$(CONFIG_SAMPLE_VFIO_MDEV_MDPY) += mdpy.o
obj-$(CONFIG_SAMPLE_VFIO_MDEV_MDPY_FB) += mdpy-fb.o
obj-$(CONFIG_SAMPLE_VFIO_MDEV_MBOCHS) += mbochs.o
+obj-$(CONFIG_SAMPLE_VIRTIO_MDEV_NET) += mvnet.o
new file mode 100644
@@ -0,0 +1,686 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Mediated virtual virtio-net device driver.
+ *
+ * Copyright (c) 2019, Red Hat Inc. All rights reserved.
+ * Author: Jason Wang <jasowang@redhat.com>
+ *
+ * Sample driver that creates mdev device that simulates ethernet loopback
+ * device.
+ *
+ * Usage:
+ *
+ * # modprobe virtio_mdev
+ * # modprobe mvnet
+ * # cd /sys/devices/virtual/mvnet/mvnet/mdev_supported_types/mvnet-virtio
+ * # echo "83b8f4f2-509f-382f-3c1e-e6bfe0fa1001" > ./create
+ * # cd devices/83b8f4f2-509f-382f-3c1e-e6bfe0fa1001
+ * # ls -d virtio0
+ * virtio0
+ */
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/device.h>
+#include <linux/kernel.h>
+#include <linux/fs.h>
+#include <linux/poll.h>
+#include <linux/slab.h>
+#include <linux/sched.h>
+#include <linux/wait.h>
+#include <linux/uuid.h>
+#include <linux/iommu.h>
+#include <linux/sysfs.h>
+#include <linux/file.h>
+#include <linux/etherdevice.h>
+#include <linux/mdev.h>
+#include <linux/vringh.h>
+#include <linux/mdev_virtio_ops.h>
+#include <uapi/linux/virtio_config.h>
+#include <uapi/linux/virtio_net.h>
+
+#define VERSION_STRING "0.1"
+#define DRIVER_AUTHOR "Red Hat Corporation"
+
+#define MVNET_CLASS_NAME "mvnet"
+#define MVNET_NAME "mvnet"
+
+/*
+ * Global Structures
+ */
+
+static struct mvnet_dev {
+ struct class *vd_class;
+ struct idr vd_idr;
+ struct device dev;
+} mvnet_dev;
+
+struct mvnet_virtqueue {
+ struct vringh vring;
+ struct vringh_kiov iov;
+ unsigned short head;
+ bool ready;
+ u64 desc_addr;
+ u64 device_addr;
+ u64 driver_addr;
+ u32 num;
+ void *private;
+ irqreturn_t (*cb)(void *data);
+};
+
+#define MVNET_QUEUE_ALIGN PAGE_SIZE
+#define MVNET_QUEUE_MAX 256
+#define MVNET_DEVICE_ID 0x1
+#define MVNET_VENDOR_ID 0
+
+u64 mvnet_features = (1ULL << VIRTIO_F_ANY_LAYOUT) |
+ (1ULL << VIRTIO_F_VERSION_1) |
+ (1ULL << VIRTIO_F_IOMMU_PLATFORM);
+
+/* State of each mdev device */
+struct mvnet_state {
+ struct mvnet_virtqueue vqs[2];
+ struct work_struct work;
+ /* spinlock to synchronize virtqueue state */
+ spinlock_t lock;
+ struct mdev_device *mdev;
+ struct virtio_net_config config;
+ void *buffer;
+ u32 status;
+ u32 generation;
+ u64 features;
+ struct list_head next;
+};
+
+static struct mutex mdev_list_lock;
+static struct list_head mdev_devices_list;
+
+static void mvnet_queue_ready(struct mvnet_state *mvnet, unsigned int idx)
+{
+ struct mvnet_virtqueue *vq = &mvnet->vqs[idx];
+ int ret;
+
+ ret = vringh_init_kern(&vq->vring, mvnet_features, MVNET_QUEUE_MAX,
+ false, (struct vring_desc *)vq->desc_addr,
+ (struct vring_avail *)vq->driver_addr,
+ (struct vring_used *)vq->device_addr);
+}
+
+static void mvnet_vq_reset(struct mvnet_virtqueue *vq)
+{
+ vq->ready = 0;
+ vq->desc_addr = 0;
+ vq->driver_addr = 0;
+ vq->device_addr = 0;
+ vq->cb = NULL;
+ vq->private = NULL;
+ vringh_init_kern(&vq->vring, mvnet_features, MVNET_QUEUE_MAX,
+ false, 0, 0, 0);
+}
+
+static void mvnet_reset(struct mvnet_state *mvnet)
+{
+ int i;
+
+ for (i = 0; i < 2; i++)
+ mvnet_vq_reset(&mvnet->vqs[i]);
+
+ mvnet->features = 0;
+ mvnet->status = 0;
+ ++mvnet->generation;
+}
+
+static void mvnet_work(struct work_struct *work)
+{
+ struct mvnet_state *mvnet = container_of(work, struct
+ mvnet_state, work);
+ struct mvnet_virtqueue *txq = &mvnet->vqs[1];
+ struct mvnet_virtqueue *rxq = &mvnet->vqs[0];
+ size_t read, write, total_write;
+ int err;
+ int pkts = 0;
+
+ spin_lock(&mvnet->lock);
+
+ if (!txq->ready || !rxq->ready)
+ goto out;
+
+ while (true) {
+ total_write = 0;
+ err = vringh_getdesc_kern(&txq->vring, &txq->iov, NULL,
+ &txq->head, GFP_ATOMIC);
+ if (err <= 0)
+ break;
+
+ err = vringh_getdesc_kern(&rxq->vring, NULL, &rxq->iov,
+ &rxq->head, GFP_ATOMIC);
+ if (err <= 0) {
+ vringh_complete_kern(&txq->vring, txq->head, 0);
+ break;
+ }
+
+ while (true) {
+ read = vringh_iov_pull_kern(&txq->iov, mvnet->buffer,
+ PAGE_SIZE);
+ if (read <= 0)
+ break;
+
+ write = vringh_iov_push_kern(&rxq->iov, mvnet->buffer,
+ read);
+ if (write <= 0)
+ break;
+
+ total_write += write;
+ }
+
+ /* Make sure data is wrote before advancing index */
+ smp_wmb();
+
+ vringh_complete_kern(&txq->vring, txq->head, 0);
+ vringh_complete_kern(&rxq->vring, rxq->head, total_write);
+
+ /* Make sure used is visible before rasing the interrupt. */
+ smp_wmb();
+
+ local_bh_disable();
+ if (txq->cb)
+ txq->cb(txq->private);
+ if (rxq->cb)
+ rxq->cb(rxq->private);
+ local_bh_enable();
+
+ if (++pkts > 4) {
+ schedule_work(&mvnet->work);
+ goto out;
+ }
+ }
+
+out:
+ spin_unlock(&mvnet->lock);
+}
+
+static dma_addr_t mvnet_map_page(struct device *dev, struct page *page,
+ unsigned long offset, size_t size,
+ enum dma_data_direction dir,
+ unsigned long attrs)
+{
+ /* Vringh can only use HVA */
+ return (dma_addr_t)(page_address(page) + offset);
+}
+
+static void mvnet_unmap_page(struct device *dev, dma_addr_t dma_addr,
+ size_t size, enum dma_data_direction dir,
+ unsigned long attrs)
+{
+}
+
+static void *mvnet_alloc_coherent(struct device *dev, size_t size,
+ dma_addr_t *dma_addr, gfp_t flag,
+ unsigned long attrs)
+{
+ void *addr = kmalloc(size, flag);
+
+ if (!addr)
+ *dma_addr = DMA_MAPPING_ERROR;
+ else
+ *dma_addr = (dma_addr_t)addr;
+
+ return addr;
+}
+
+static void mvnet_free_coherent(struct device *dev, size_t size,
+ void *vaddr, dma_addr_t dma_addr,
+ unsigned long attrs)
+{
+ kfree((void *)dma_addr);
+}
+
+static const struct dma_map_ops mvnet_dma_ops = {
+ .map_page = mvnet_map_page,
+ .unmap_page = mvnet_unmap_page,
+ .alloc = mvnet_alloc_coherent,
+ .free = mvnet_free_coherent,
+};
+
+static const struct mdev_virtio_device_ops mdev_virtio_ops;
+
+static int mvnet_create(struct kobject *kobj, struct mdev_device *mdev)
+{
+ struct mvnet_state *mvnet;
+ struct virtio_net_config *config;
+ struct device *dev = mdev_dev(mdev);
+
+ if (!mdev)
+ return -EINVAL;
+
+ mvnet = kzalloc(sizeof(*mvnet), GFP_KERNEL);
+ if (!mvnet)
+ return -ENOMEM;
+
+ mvnet->buffer = kmalloc(PAGE_SIZE, GFP_KERNEL);
+ if (!mvnet->buffer) {
+ kfree(mvnet);
+ return -ENOMEM;
+ }
+
+ config = &mvnet->config;
+ config->mtu = 1500;
+ config->status = VIRTIO_NET_S_LINK_UP;
+ eth_random_addr(config->mac);
+
+ INIT_WORK(&mvnet->work, mvnet_work);
+
+ spin_lock_init(&mvnet->lock);
+ mvnet->mdev = mdev;
+ mdev_set_drvdata(mdev, mvnet);
+
+ mutex_lock(&mdev_list_lock);
+ list_add(&mvnet->next, &mdev_devices_list);
+ mutex_unlock(&mdev_list_lock);
+
+ dev->coherent_dma_mask = DMA_BIT_MASK(64);
+ set_dma_ops(dev, &mvnet_dma_ops);
+
+ mdev_set_virtio_ops(mdev, &mdev_virtio_ops);
+
+ return 0;
+}
+
+static int mvnet_remove(struct mdev_device *mdev)
+{
+ struct mvnet_state *mds, *tmp_mds;
+ struct mvnet_state *mvnet = mdev_get_drvdata(mdev);
+ int ret = -EINVAL;
+
+ mutex_lock(&mdev_list_lock);
+ list_for_each_entry_safe(mds, tmp_mds, &mdev_devices_list, next) {
+ if (mvnet == mds) {
+ list_del(&mvnet->next);
+ mdev_set_drvdata(mdev, NULL);
+ kfree(mvnet->buffer);
+ kfree(mvnet);
+ ret = 0;
+ break;
+ }
+ }
+ mutex_unlock(&mdev_list_lock);
+
+ return ret;
+}
+
+static ssize_t
+sample_mvnet_dev_show(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ if (mdev_from_dev(dev))
+ return sprintf(buf, "This is MDEV %s\n", dev_name(dev));
+
+ return sprintf(buf, "\n");
+}
+
+static DEVICE_ATTR_RO(sample_mvnet_dev);
+
+static struct attribute *mvnet_dev_attrs[] = {
+ &dev_attr_sample_mvnet_dev.attr,
+ NULL,
+};
+
+static const struct attribute_group mvnet_dev_group = {
+ .name = "mvnet_dev",
+ .attrs = mvnet_dev_attrs,
+};
+
+static const struct attribute_group *mvnet_dev_groups[] = {
+ &mvnet_dev_group,
+ NULL,
+};
+
+static ssize_t
+sample_mdev_dev_show(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ if (mdev_from_dev(dev))
+ return sprintf(buf, "This is MDEV %s\n", dev_name(dev));
+
+ return sprintf(buf, "\n");
+}
+
+static DEVICE_ATTR_RO(sample_mdev_dev);
+
+static struct attribute *mdev_dev_attrs[] = {
+ &dev_attr_sample_mdev_dev.attr,
+ NULL,
+};
+
+static const struct attribute_group mdev_dev_group = {
+ .name = "vendor",
+ .attrs = mdev_dev_attrs,
+};
+
+static const struct attribute_group *mdev_dev_groups[] = {
+ &mdev_dev_group,
+ NULL,
+};
+
+#define MVNET_STRING_LEN 16
+
+static ssize_t
+name_show(struct kobject *kobj, struct device *dev, char *buf)
+{
+ char name[MVNET_STRING_LEN];
+ const char *name_str = "virtio-net";
+
+ snprintf(name, MVNET_STRING_LEN, "%s", dev_driver_string(dev));
+ if (!strcmp(kobj->name, name))
+ return sprintf(buf, "%s\n", name_str);
+
+ return -EINVAL;
+}
+
+static MDEV_TYPE_ATTR_RO(name);
+
+static ssize_t
+available_instances_show(struct kobject *kobj, struct device *dev, char *buf)
+{
+ return sprintf(buf, "%d\n", INT_MAX);
+}
+
+static MDEV_TYPE_ATTR_RO(available_instances);
+
+static ssize_t device_api_show(struct kobject *kobj, struct device *dev,
+ char *buf)
+{
+ return sprintf(buf, "%s\n", VIRTIO_MDEV_DEVICE_API_STRING);
+}
+
+static MDEV_TYPE_ATTR_RO(device_api);
+
+static struct attribute *mdev_types_attrs[] = {
+ &mdev_type_attr_name.attr,
+ &mdev_type_attr_device_api.attr,
+ &mdev_type_attr_available_instances.attr,
+ NULL,
+};
+
+static struct attribute_group mdev_type_group = {
+ .name = "virtio",
+ .attrs = mdev_types_attrs,
+};
+
+/* TBD: "vhost" type */
+
+static struct attribute_group *mdev_type_groups[] = {
+ &mdev_type_group,
+ NULL,
+};
+
+static int mvnet_set_vq_address(struct mdev_device *mdev, u16 idx,
+ u64 desc_area, u64 driver_area, u64 device_area)
+{
+ struct mvnet_state *mvnet = mdev_get_drvdata(mdev);
+ struct mvnet_virtqueue *vq = &mvnet->vqs[idx];
+
+ vq->desc_addr = desc_area;
+ vq->driver_addr = driver_area;
+ vq->device_addr = device_area;
+
+ return 0;
+}
+
+static void mvnet_set_vq_num(struct mdev_device *mdev, u16 idx, u32 num)
+{
+ struct mvnet_state *mvnet = mdev_get_drvdata(mdev);
+ struct mvnet_virtqueue *vq = &mvnet->vqs[idx];
+
+ vq->num = num;
+}
+
+static void mvnet_kick_vq(struct mdev_device *mdev, u16 idx)
+{
+ struct mvnet_state *mvnet = mdev_get_drvdata(mdev);
+ struct mvnet_virtqueue *vq = &mvnet->vqs[idx];
+
+ if (vq->ready)
+ schedule_work(&mvnet->work);
+}
+
+static void mvnet_set_vq_cb(struct mdev_device *mdev, u16 idx,
+ struct virtio_mdev_callback *cb)
+{
+ struct mvnet_state *mvnet = mdev_get_drvdata(mdev);
+ struct mvnet_virtqueue *vq = &mvnet->vqs[idx];
+
+ vq->cb = cb->callback;
+ vq->private = cb->private;
+}
+
+static void mvnet_set_vq_ready(struct mdev_device *mdev, u16 idx, bool ready)
+{
+ struct mvnet_state *mvnet = mdev_get_drvdata(mdev);
+ struct mvnet_virtqueue *vq = &mvnet->vqs[idx];
+
+ spin_lock(&mvnet->lock);
+ vq->ready = ready;
+ if (vq->ready)
+ mvnet_queue_ready(mvnet, idx);
+ spin_unlock(&mvnet->lock);
+}
+
+static bool mvnet_get_vq_ready(struct mdev_device *mdev, u16 idx)
+{
+ struct mvnet_state *mvnet = mdev_get_drvdata(mdev);
+ struct mvnet_virtqueue *vq = &mvnet->vqs[idx];
+
+ return vq->ready;
+}
+
+static int mvnet_set_vq_state(struct mdev_device *mdev, u16 idx, u64 state)
+{
+ struct mvnet_state *mvnet = mdev_get_drvdata(mdev);
+ struct mvnet_virtqueue *vq = &mvnet->vqs[idx];
+ struct vringh *vrh = &vq->vring;
+
+ spin_lock(&mvnet->lock);
+ vrh->last_avail_idx = state;
+ spin_unlock(&mvnet->lock);
+
+ return 0;
+}
+
+static u64 mvnet_get_vq_state(struct mdev_device *mdev, u16 idx)
+{
+ struct mvnet_state *mvnet = mdev_get_drvdata(mdev);
+ struct mvnet_virtqueue *vq = &mvnet->vqs[idx];
+ struct vringh *vrh = &vq->vring;
+
+ return vrh->last_avail_idx;
+}
+
+static u16 mvnet_get_vq_align(struct mdev_device *mdev)
+{
+ return MVNET_QUEUE_ALIGN;
+}
+
+static u64 mvnet_get_features(struct mdev_device *mdev)
+{
+ return mvnet_features;
+}
+
+static int mvnet_set_features(struct mdev_device *mdev, u64 features)
+{
+ struct mvnet_state *mvnet = mdev_get_drvdata(mdev);
+
+ /* DMA mapping must be done by driver */
+ if (!(features & (1ULL << VIRTIO_F_IOMMU_PLATFORM)))
+ return -EINVAL;
+
+ mvnet->features = features & mvnet_features;
+
+ return 0;
+}
+
+static void mvnet_set_config_cb(struct mdev_device *mdev,
+ struct virtio_mdev_callback *cb)
+{
+ /* We don't support config interrupt */
+}
+
+static u16 mvnet_get_vq_num_max(struct mdev_device *mdev)
+{
+ return MVNET_QUEUE_MAX;
+}
+
+static u32 mvnet_get_device_id(struct mdev_device *mdev)
+{
+ return MVNET_DEVICE_ID;
+}
+
+static u32 mvnet_get_vendor_id(struct mdev_device *mdev)
+{
+ return MVNET_VENDOR_ID;
+}
+
+static u8 mvnet_get_status(struct mdev_device *mdev)
+{
+ struct mvnet_state *mvnet = mdev_get_drvdata(mdev);
+
+ return mvnet->status;
+}
+
+static void mvnet_set_status(struct mdev_device *mdev, u8 status)
+{
+ struct mvnet_state *mvnet = mdev_get_drvdata(mdev);
+
+ mvnet->status = status;
+
+ if (status == 0) {
+ spin_lock(&mvnet->lock);
+ mvnet_reset(mvnet);
+ spin_unlock(&mvnet->lock);
+ }
+}
+
+static void mvnet_get_config(struct mdev_device *mdev, unsigned int offset,
+ void *buf, unsigned int len)
+{
+ struct mvnet_state *mvnet = mdev_get_drvdata(mdev);
+
+ if (offset + len < sizeof(struct virtio_net_config))
+ memcpy(buf, &mvnet->config + offset, len);
+}
+
+static void mvnet_set_config(struct mdev_device *mdev, unsigned int offset,
+ const void *buf, unsigned int len)
+{
+ /* No writable config supportted by mvnet */
+}
+
+static u32 mvnet_get_generation(struct mdev_device *mdev)
+{
+ struct mvnet_state *mvnet = mdev_get_drvdata(mdev);
+
+ return mvnet->generation;
+}
+
+static const struct mdev_virtio_device_ops mdev_virtio_ops = {
+ .set_vq_address = mvnet_set_vq_address,
+ .set_vq_num = mvnet_set_vq_num,
+ .kick_vq = mvnet_kick_vq,
+ .set_vq_cb = mvnet_set_vq_cb,
+ .set_vq_ready = mvnet_set_vq_ready,
+ .get_vq_ready = mvnet_get_vq_ready,
+ .set_vq_state = mvnet_set_vq_state,
+ .get_vq_state = mvnet_get_vq_state,
+ .get_vq_align = mvnet_get_vq_align,
+ .get_features = mvnet_get_features,
+ .set_features = mvnet_set_features,
+ .set_config_cb = mvnet_set_config_cb,
+ .get_vq_num_max = mvnet_get_vq_num_max,
+ .get_device_id = mvnet_get_device_id,
+ .get_vendor_id = mvnet_get_vendor_id,
+ .get_status = mvnet_get_status,
+ .set_status = mvnet_set_status,
+ .get_config = mvnet_get_config,
+ .set_config = mvnet_set_config,
+ .get_generation = mvnet_get_generation,
+};
+
+static const struct mdev_parent_ops mdev_fops = {
+ .owner = THIS_MODULE,
+ .dev_attr_groups = mvnet_dev_groups,
+ .mdev_attr_groups = mdev_dev_groups,
+ .supported_type_groups = mdev_type_groups,
+ .create = mvnet_create,
+ .remove = mvnet_remove,
+};
+
+static void mvnet_device_release(struct device *dev)
+{
+ dev_dbg(dev, "mvnet: released\n");
+}
+
+static int __init mvnet_dev_init(void)
+{
+ int ret = 0;
+
+ pr_info("mvnet_dev: %s\n", __func__);
+
+ memset(&mvnet_dev, 0, sizeof(mvnet_dev));
+
+ idr_init(&mvnet_dev.vd_idr);
+
+ mvnet_dev.vd_class = class_create(THIS_MODULE, MVNET_CLASS_NAME);
+
+ if (IS_ERR(mvnet_dev.vd_class)) {
+ pr_err("Error: failed to register mvnet_dev class\n");
+ ret = PTR_ERR(mvnet_dev.vd_class);
+ goto failed1;
+ }
+
+ mvnet_dev.dev.class = mvnet_dev.vd_class;
+ mvnet_dev.dev.release = mvnet_device_release;
+ dev_set_name(&mvnet_dev.dev, "%s", MVNET_NAME);
+
+ ret = device_register(&mvnet_dev.dev);
+ if (ret)
+ goto failed2;
+
+ ret = mdev_register_device(&mvnet_dev.dev, &mdev_fops);
+ if (ret)
+ goto failed3;
+
+ mutex_init(&mdev_list_lock);
+ INIT_LIST_HEAD(&mdev_devices_list);
+
+ goto all_done;
+
+failed3:
+
+ device_unregister(&mvnet_dev.dev);
+failed2:
+ class_destroy(mvnet_dev.vd_class);
+
+failed1:
+all_done:
+ return ret;
+}
+
+static void __exit mvnet_dev_exit(void)
+{
+ mvnet_dev.dev.bus = NULL;
+ mdev_unregister_device(&mvnet_dev.dev);
+
+ device_unregister(&mvnet_dev.dev);
+ idr_destroy(&mvnet_dev.vd_idr);
+ class_destroy(mvnet_dev.vd_class);
+ mvnet_dev.vd_class = NULL;
+ pr_info("mvnet_dev: Unloaded!\n");
+}
+
+module_init(mvnet_dev_init)
+module_exit(mvnet_dev_exit)
+
+MODULE_LICENSE("GPL v2");
+MODULE_INFO(supported, "Simulate loopback ethernet device over mdev");
+MODULE_VERSION(VERSION_STRING);
+MODULE_AUTHOR(DRIVER_AUTHOR);